diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 67570f74566c..c78f1593600b 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -430,19 +430,22 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, if (!handle->cur) return -EINVAL; - offset = alloc_swapdev_block(root_swap); - error = write_page(buf, offset, hb); - if (error) - return error; - handle->cur->entries[handle->k++] = offset; + + /* + * If the current map page is full, allocate and link next one first. + * Delaying this until here avoids writing an empty swap map page when + * the image size is an exact MAP_PAGE_ENTRIES multiple. + */ if (handle->k >= MAP_PAGE_ENTRIES) { offset = alloc_swapdev_block(root_swap); if (!offset) return -ENOSPC; + handle->cur->next_swap = offset; error = write_page(handle->cur, handle->cur_swap, hb); if (error) - goto out; + return error; + clear_page(handle->cur); handle->cur_swap = offset; handle->k = 0; @@ -450,7 +453,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, if (hb && low_free_pages() <= handle->reqd_free_pages) { error = hib_wait_io(hb); if (error) - goto out; + return error; /* * Recalculate the number of required free pages, to * make sure we never take more than half. @@ -458,14 +461,21 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, handle->reqd_free_pages = reqd_free_pages(); } } - out: - return error; + + offset = alloc_swapdev_block(root_swap); + error = write_page(buf, offset, hb); + if (error) + return error; + handle->cur->entries[handle->k++] = offset; + return 0; } static int flush_swap_writer(struct swap_map_handle *handle) { - if (handle->cur && handle->cur_swap) + if (handle->cur && handle->cur_swap && handle->k) return write_page(handle->cur, handle->cur_swap, NULL); + else if (handle->cur && handle->cur_swap) + return 0; else return -EINVAL; }